Hi there! If you get in on Singapore pretty close to the start, dc seem to commit the facts to memory quite naturally just from the way mental math is presented, both in the HOD hands-on plans and in the Singapore style of doing things. Both of my dc seem to be knowing their addition facts quite well in Singapore 2A, and their subtraction facts quite well in 2B. If they don't, then I'd help them along with it by having them do math flashcards, one set of numbers at a time, i.e all the +0's, then all the +1's, etc. Then combining them as you go. By the time my ds was completing 3B/4A, he seemed to have his multiplication/division facts down well. You are coming into Singapore early enough that it should be just fine! I'd just be sure to do all of the HOD hands-on plans, as well as teach the way Singapore's directions have you explain things, and you'll be set. If your older dd is going to do Singapore 2A/2B, I'd personally get the Bigger Hearts manual for her to do the HOD hands-on math along with the 2A/2B workbooks. If you haven't given your dc the free Singapore math placement test, I'd do that to place them , as it's very accurate. Don't be upset if they test a semester or year below their grade level, as Singapore is commonly thought to be about a year advanced. Here's a link to the placement test, just click on the placement button:
www.singaporemath.com
HTH! It think your dc will thrive with Singapore and with all of Beyond - it's a treat to teach from and to learn from!
In Christ,
Julie